Donald Trump threatened to "totally destroy North Korea" if the US is forced to defend itself or allies against aggression in a strongly worded address to the general assembly of the United Nations.

Mr Trump, speaking in his home city of New York, also took aim at Iran in his speech at the world body's headquarters.

The US president described North Korean leader Kim Jong Un as a "rocket man on a suicide mission" following a series of weapons tests by the Pyongyang regime.

He also said the Iranian government was running an "economically depleted rogue state" whose chief export is violence.

Image provided by the U.S. Navy, the guided-missile destroyer USS Porter (DDG 78) launches a tomahawk land attack missile in the Mediterranean Sea as the United States blasted a Syrian air base with a barrage of cruise missiles in fiery retaliation for a gruesome chemical weapons attack against civilians earlier in the week